Study On The Tissue Culture Of Malus Asiatica

Malus asiatica, belongs to Rosaceae, Malus, deciduous leaf small tree, and is one of theornamental trees with beautiful flowers and fruits. Malus asiatica contains a variety ofvitamins and minerals beneficial to the human body with rich nutritive value. Now, there is noresearch on the tissue culture of Malus asiatica in the domestic, people often take the method ofgrafting with low propagation coefficient, which can not meet the demand of production, thusseverely limits the development of Malus asiatica. The thesis is a study on the tissue culture ofMalus asiatica, so as to find the effective way of improving the quantity and quality of Malusasiatica.This thesis uses the tissue culture technology and orthogonal design, and uses the stems ofMalus asiatica as explants, through the establishment of explants aseptic system, introduction,proliferation and root of buds, for the purpose of rapid reproduction. The main conclusions areas follows:1. The stem with bud is used as explants, and the results showed that the best disinfectiontreatment for hydroponics explants is:75%alcohol30s+0.1%HgCl24min; the best disinfectiontreatment for explants which were puck in the wild is:75%alcohol for30s+0.1%HgCl2for7min.2. The explants of Malus asiatica which were grown in water in February have lowerinfection rate of bacteria and browning rate,13.33%,14.44%, respectively with the higheststerile survival rate72.22%. The best time to pick explants is in February.3. The sterile survival rate of young stem, semi lignified stem and lignified stem are65.56%,70.00%,42.22%respectively. From that, the effect of the same sterilization of differentexplants parts is: semi lignified stem> young stem> lignified stem.4. Transferring cultures to fresh medium every seven days is the best way to preventbrowning. The browning rate has decreased to13.33%. Secondly, adding AC to medium, itsbrowning rate is18.89%. And the effect of PVP is not obvious, and the browning rate is just20%.5. The effect of bud induction for three kinds of explants: semi lignified stem>youngstem> lignified. The bud of semi lignified sprouts fast, just in7-12d, and the bud is vigorous.6. Adopting orthogonal design, the results show that the effect of culture medium on budintroduction is greatest, secondly is6-BA, and the effect of NAA is the smallest. The optimumculture medium is MS+6-BA2.0mg/L+NAA0.3mg/L.7. Adopting orthogonal design, the results show that the main factors affecting propagationcoefficient is6-BA, secondly NAA. And6-BA has significant difference in the level of0.01,indicating that the best medium for shoot proliferation subculture is: MS+6-BA2.0mg/L+NAA0.25mg/L.8. Our experiments failed to obtain the rooting tube plantlets of Malus asiatica, whichmaybe caused by the following: first, inappropriate amount of auxins; second, different quality of tissue culture; third, inpaaropriate reducing sprout and rooted basic medium;fourth, theinfluence of the varieties of rooting performance.